Non-Fermi-liquid behavior at anti-ferromagnetic quantum critical point in heavy fermion system Ce(Cu1−x_{1-x}Cox_x)2_2Ge2_2

Polycrystalline samples of Ce(Cu$_{1-x}$Co$_x$)$_2$Ge$_2$ were investigated by means of electrical resistivity $\rho$($T$), magnetic susceptibility $\chi$($T$), specific heat $C$$_p$($T$) and thermo electric power $S$($T$) measurements. The long-range antiferromagnetic (AFM) order, which set in at $T$$_N$ = 4.1 K in CeCu$_2$Ge$_2$, is suppressed by non-iso-electronic cobalt (Co) doping at a critical value of the concentration $x$$_c$ = 0.6, accompanied by non-Fermi liquid (NFL) behavior inferred from the power law dependence of heat capacity and susceptibility i.e. $C$($T$)/$T$ and $\chi$($T$) $\propto$ $T$$^{-1+\lambda}$ down to 0.4 K, along with a clear deviation from $T$$^2$ behavior of the electrical resistivity. However, we have not seen any superconducting phase in the quantum critical regime down to 0.4 K.Comment: 8 pages, 11 figure

Novel High Voltage Electrodes for Li-ion Batteries

An alternate family of “high” voltage (where the equilibrium voltage lies between 3.6 V and 4.2 V) polyanion cathode materials is reported in this thesis with the objective of improving specific energy density (Wh/kg) and developing a better understanding of polyanion electrochemistry. The electrochemical properties, synthesis and the structure of novel fluorosulfate materials crystallizing in the tavorite and the triplite type mineral structures are described. These materials display highest discharge voltages reported for any Fe2+/Fe3+ redox couple. LiFeSO4F was prepared in both the tavorite and the triplite polymorphs using inexpensive and scalable methods. Complete structural characterization was performed using X-ray and neutron based diffraction methods. A rapid synthesis of fluorosulfates can be achieved by using microwave heating. The local rapid heating created by the microwaves generates nanocrystalline LiFeSO4F tavorite with defects that induce significant microstrain. To date, this is unique to the microwave synthesis method. Phase transformation to the more stable triplite framework, facilitated by the lattice defects which include hydroxyl groups, is therefore easily triggered. The formation of nanocrystalline tavorite leads to nanocrystalline triplite, which greatly favors its electrochemical performance because of the inherently disordered nature of the triplite structure. Direct synthesis of the electrochemically active triplite type compound can be carried out either by extending the duration of the solvothermal reactions or by the partial substitution of Fe by Mn to produce LiFe1-xMnxSO4F. This study, overall, has led to a better understanding of the transformation of tavorite to the triplite phase. To examine Li and the Na ion conduction and their correlation with the electrochemical performance of 3-D, 2-D and 1-D ion conductors, atomistic scale simulations have been used to investigate tavorite type LiFeSO4F, NaFeSO4F, olivine type NaMPO4 (M= Fe, Mn, Fe0.5Mn0.5) and layered Na2FePO4F. These calculations predict high mobility of the Li-ion in the tavorite type LiFeSO4F but sluggish Na-ion transport in iso-structural NaFeSO4F. High mobility of the Na-ion is predicted for phosphate layered and olivine structures. Finally, the synthesis and structural details of NaMSO4F (M=Fe, Mn) and NH4MSO4F (M=Fe, Mn) are presented in the last chapter to show the structural diversity present in the fluorosulfate family

Learning from Past in the Commercial Air Transport Industry: A Bibliometric Analysis and Systematic Literature Review in the Safety Management Framework

In the commercial air transport industry, numerous accidents have occurred because stakeholders have failed to learn lessons from the past. The reactive hazard identification (HI) methodology in the current regulatory safety management framework provides a fresh opportunity to negotiate the challenges of the air transportation sector\u27s predicted growth and societal safety expectations. In the regulatory framework, ‘learning from the past’ is related to the reactive method of HI, and it is viewed as a data-driven decision-making process in this review. This literature review aims to investigate academic literature on ‘learning from the past’ in the aviation industry to comprehend an overview and identify the gaps in the scholarly approaches and regulatory provisions. The data sources for the review comprise the research articles indexed in Scopus and Web of Science databases from 2000 to July 2023. This review follows a mixed methodology consisting of a bibliometric analysis using an R tool to develop a broad understanding and, for specific gap identification, a systematic literature review in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All 283 studies are included in the bibliometric analysis, while only 24 studies are found eligible based on the predefined inclusion/exclusion criteria for systematic review. The results reveal that ‘learning from the past’ has not been explored as a data-driven decision-making process for HI in aviation industry settings. The stagewise barriers in the learning process and the impact of each stage on overall learning remain unexplored. The regulatory provisions associated with safety information from aviation activities\u27 resilient (positive) outcomes for learning from the past purpose, organizational safety culture, and harmonization with the criminal justice system are vulnerable

The conformational phase diagram of charged polymers in the presence of attractive bridging crowders

Using extensive molecular dynamics simulations, we obtain the conformational phase diagram of a charged polymer in the presence of oppositely charged counterions and neutral attractive crowders for monovalent, divalent and trivalent counterion valencies. We demonstrate that the charged polymer can exist in three phases: (1) an extended phase for low charge densities and weak polymer-crowder attractive interactions ($CE$), (2) a collapsed phase for high charge densities and weak polymer-crowder attractive interactions, primarily driven by counterion condensation ($CCI$), and (3) a collapsed phase for strong polymer-crowder attractive interactions, irrespective of the charge density, driven by crowders acting as bridges or crosslinks ($CCB$). Importantly, the simulations reveal that the interaction with crowders can induce collapse, despite the presence of strong repulsive electrostatic interactions, and can replace condensed counterions to facilitate a direct transition from the $CCI$ and $CE$ phases to the $CCB$ phase.Comment: 12 pages, 10 figure

Marcus inverted region in the photoinduced electron transfer reactions of ruthenium(ii)-polypyridine complexes with phenolate ions.

Ruthenium (II)- polypyridy1 complexes of similar size but with variable reduction potential undergo efficient photoinduced electron- transfer reactions with phenolate ions in aqueous medium. All these reactions are exergonic and are in accordance with the Marcus theory of electron transfer. At high negative G° Marcus inverted region is observed in this bimolecular photoinduced charge separation reaction

Detailing provisions to control bar buckling in ductile RC walls

Bar buckling in ductile reinforced concrete (RC) walls is a commonly observed failure mode which limits their deformation capacity. To delay this undesirable failure mode in RC walls, most design codes emphasize on restricting the spacing of transverse reinforcement in the plastic hinges of RC walls. On the other hand, past research has shown that bar buckling in RC structures could span multiple tie spacings and the efficacy of transverse reinforcement to restrain bars against buckling is a function of the effective axial stiffness of transverse reinforcement in addition to the spacing of transverse reinforcement. To overcome these design limitations, a new mechanics-based design procedure to control bar buckling in ductile RC walls was recently proposed. In this paper, the newly developed guidelines for designing transverse reinforcement to control bar buckling in RC walls are summarized. Restrictions on both the axial stiffness of the tie legs and spacing of transverse reinforcement along the longitudinal reinforcing bars are proposed to confine bar buckling between the consecutive stirrups. Further, the average cyclic stress-strain response of reinforcing bars is utilized to limit compressive stress degradation in reinforcing bars until the design ductility demands are met

STRESS MANAGEMENT TECHNIQUE FOR ATHLETES DURING SPORTS: A CRITICAL REVIEW

Stressors have a major influence upon mood, our sense of well-being, behavior, and health. Acute stress responses in young, healthy individuals may be adaptive and typically do not impose a health burden. However, if the threat is unremitting, particularly in older or unhealthy individuals, the long-term effects of stressors can damage health. This paper attempts to look at the strategies for sports coaches in managing stressful situations in sports competitions. This paper therefore, writes in the introduction, the concepts of stress, competition based stress, management, stress management in sports, stress in sports psychology. The paper also examines the sources of stress. It looks critically at the levels of stress in competitive sports. The relationship between psychosocial stressors and disease is affected by the nature, number, and persistence of the stressors as well as by the individual’s biological vulnerability (i.e., genetics, constitutional factors), psychosocial resources, and learned patterns of coping. Psychosocial interventions have proven useful for treating stress-related disorders and may influence the course of chronic diseases. The paper also highlights some specific stress management strategies which sports coaches have to employ to aid excellent performance in sports competition. It also identifies the educational implications of stress management in sports competitions. Keywords: Psychosocial stressors, Stress responses, Sports, psychosocial interventions, Stressor interactions, Stress management

Dielectric Properties and AC Conductivity Measurements of Amorphous Ge15Se85 Glass

In the present study, investigations of dielectric parameters viz dielectric constant (), dielectric loss () and AC conductivity measurements have been made for bulk chalcogenide Ge15Se85 glass in the frequency range 10 to 500 kHz within the temperature range from 300 to 390 K. The variation of dielectric constant and dielectric loss with frequency at room temperature is reported and discussed in the investigated glassy binary alloy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3101